We had her on a high protein grainfree diet Taste of the wild Rocky mountain Feline formula.

Canned or dry?

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Originally Posted by Lillycat

The vet told us we now have to feed her Purina One Urinary tract health formula 1/4th cup morning 1/4th cup in the evening,

Putting a cat with urinary tract issues on dry food is completely illogical and inappropriate. Did you read the link a couple posts above about diet and it's relationship to FLUTD? Wet food is the key.

Quote:

Originally Posted by Lillycat

As for her litter box it is a covered litter box she uses it regularly but just goes outside also.

I'd suggest picking up another litter box, this one uncovered, and seeing if an additional box helps. Bengals tend to be rather large cats and there isn't a single covered box on the market that I would consider big enough for even a regular sized cat. Even though she is still using it, she may prefer something larger and uncovered, like an under-the-bed storage box.

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Originally Posted by Lillycat

We use a clumping litter from Purina.

Scented or unscented?

Quote:

Originally Posted by Lillycat

the cat is meowing by our door all night long and at the front door SoI am now thinking she may not be fixed (she doesnt do this at all during the day and she gets lots of attenton from me because I am home most all day unless I have an errand to run)

A cat in heat will be pretty randy day and night, so if she's behaving "normally" during the day, I doubt that's the issue. Do you know much about her history? Perhaps her previous owner let her out at night? Could also be that she's still adapting to her new home and feels a little insecure. Lots of interactive play time before bed might help.